Electrical insulator



Dec. 8, 1942.

ELECTRICAL INSULATOR` Filed June 13. 1941 ATTORNEY B. B. RATZMAN2,304,204 y ductors Patented Dec. 8, 1942 UNITED STATESl'ATlEIlNlT.OFFICEi ELECTRICAL INSULATOR Borah B. Ratzman, Buttzville,N. J. Application June 13, 1941, Serial No. 397,833

3 Claims.

This invention relates to an insulator of the knob type for supportingelectrical wire con- It is especially applicable for use ininstallations of electrical Wire fences where the practice now is to usebarbed wire, even though the wire is electrified by a suitable currentwhich has a sting to it when touched by an animal within the fenceenclosure.

The usual practice in setting up electrically charged Wire fences is touse a knob type of insulator having an external circular groove near oneend of the insulator and to hold the barbed wire in the groove by asuitable tie-wire. Unless one of the barbs, which are usually spacedseveral inches apart, comes immediately adjacent the insulator and thetie-Wire, no pull strain is applied to the stake to which the insulatoris fastened, and several stakes may be missed by the barbs in thismanner, thereby allowing an undue amount of sag in the fence wire andtransmitting more strain to some stakes than to others,

I have found, from experience, that barbs are not necessary in anelectrical fence for the reason that the moment an animal touches theelectried Wire, it immediately backs away from it. By way ofillustration, I had a cow that would leap over a four or five-foot fenceas easily as a deer and no ordinary fences would keep her within bounds.As soon as I installed an electric fence and the cow came in contactwith it, she forgot her fence-jumping propensites and kept a properdistance from the Wire. The use of a plain, bare Wire materially reducesthe first cost of building the fence, as Well as increases the speedwith which the fence may be put up and removes the danger to the fencebuilder of getting scratched by the barbs. In certain localities, theposition of the fences is changed quite frequently to give differentpasturage, and

the use of the plain wire and the insulator to be' described hereinmaterially cheapens not only the first cost, but the cost of installingand setting up and changing the fence. Furthermore, by using myinsulator, the strain due to the Wire is substantially evenlydistributed ony each post. In other words, each post does its share ofsustaining the wire It is therefore the principal object of my inventionto provide an insulator which will allow al1 the advantages just pointedout to be attained.

Other and ancillary objects will be discerned from a reading of thefollowing specification,

taken in connection with the drawing, wherein: 65

Figure 1 is a plan view looking down on a section of an electrical fenceutilizing my insulator.

Figure 2 is a side elevation of Figure 1.

Figure 3 is a sectional View through the insulator and part of the postor support carrying it, showing one method of attaching the insulator tothe support.

Figure 4 is a View on the line 4--4 of Figure 3.

Figure 5 is a view on the line 5-5 of the sliding bar member shown inFigure 4, but with the side of the bar in reverse position.

Figure 6 is a view similar to Figure 3 but showing a modified form ofattaching the insulator to its support, Y l

Figure 7 is a View similar to Figure 3, but showing a still furthermodified form of attaching the insulator to a support.

Figure 8 shows the use of the insulator in the general application forsupporting an electrical conductor for any purpose Where the knob typeof insulator may be used.

In the various views wherein like numbers refer to corresponding parts,I illustrates supports to which is attached my improved form ofinsulator 2 by any one of the methods shown in Figures 3, 6 and '7. InFigure 3, the free end 3 of the irsulator, or that end away from thesupport, has a dovetail cross-channel 4 which is open at the end of thebody portion of the insulator 2. The bottom of the channel 4 has anangular groove 5 therein to receive part of a wire conductor 6. The body2 has a centrally located counter-bore 1 therein to receive the head 8of a nail 9 which is driven into the support I by a punch placed inengagement with the head 8. Preferably a Washer IIJ is used under thehead 8 of the nail, the washer I0 being preferably of some compressiblematerial such as fibre. r'Ihe body 2 of the insulator can be made of anysuitable insulating material such as lime glass, boro-silicate glass,porcelain or any other suitable insulating material, but for fencepurposes I prefer to use lime glass as it will stand considerable abuse.

Fitting in the dovetail channel 4, is a slidable bar II which hastapered sides to fit closely within the dovetail channel. The inner faceof the bar II has a groove I2 to` receive a part of the rwire 6. Thegroove I2 is preferably tapered along its length and breadth asillustrated in Figures 4 and 5 so that as' the bar II is forced into thechannel 4, it will continuously increase its grip on the wire. Thelength of the bar II, as shown in the drawing, is approximately the sameas the diameter of the knob 2 which is shown to be circular, although itmay have a different shape. The bar II may, however, be longer than thediameter of the body of the insulator 2, in which case it is morereadily moved to releasing position by taps on the advancing end of thebar which projects beyond the contour of the body 2I As shown in Figure6, the insulator 2 has a depression I3 in the side to receive the nail 9for fastening it to the support I.

In Figure '7 a screw I4, having a square shank I5 and head I6, is moldeddirectly into the insulator 2 so that the same may be attached to thesupport I by screwing it directly thereto, but in all cases the wire maybe attached to the body 2 of the insulator without disturbing thefastening means to its support.

In Figures 3 and 6 I have shown the bar II as of insulating material,but it may be of some suitable metal, as illustrated in Figure 7, suchas Zamak which is a composition of zinc and aluminum and will not rust.Furthermore, while I have shown bare wire in connection with theinsulator, the insulator is adaptable for use in Stringing insulatedconductors as usually used in household wiring and other places, inwhich case the bar I I would preferably be made of insulating material.

While certain of the details of the body of the insulator and thesliding bar may be varied, these variations are believed to come withinthe scope of the appended claims.

What I claim is:

l. An electrical insulator for a wire conducto-1' comprising a bodymember of suitable insulating material and having a transverse channelopening in one end, the sides of the channel being tapered for asubstantial distance to provide a large gripping surface with the narrowpart at the end surface of the said body, the bottom of the channelhaving a tapered groove therein to receive a part of the diameter of thewire, a slidable locking bar having tapered sides to t substantially theentire tapered sides in the body in interlocking relationship and atapered groove in the inner face of the bar to receive a part of thediameter of the wire, the small end of the taper being at thechannelentering end oi the locking bar whereby when the slide is forcedinto locking position in the channel, the wire is securely clamped in acontinuously increasing grip to the insulator, and means in the body forfastening the insulator to a support.

2. An insulator for a wire conductor comprising a body portion havingmeans for attaching it to a support and means for attaching anddetaching a conductor laterally to the body without disturbing themounting of the body on the support, said last-mentioned meanscomprising a dovetail-shaped cross-channel in the end of the insulatorand a slidable bar to snugly t the dovetail channel, the bar and bottomof the channel having cooperative grooves to continuously increase thegrip around the wire when the bar is forced into locking position and tofree the wire when the bar is forced out of the channel.

3. An insulator for a wire conductor having means for mounting it on asupport and also having means for making an easy and quick attachment ofthe wire to the insulator, said secondmentioned means comprising adovetail crosschannel opening in the free end of the insulator with agroove in the bottom of the channel to position the wire when passed latrally through the open side of the channel, and a slidable bar to iitwithin the channel in full engagement with the side walls thereof,providing a secure interlock and having a groove in its inner face toincreasingly grip the wire in cooperation with the channel groove as thebar is forced within the channel.

BORAH B. RATZMAN.

